WO2018154931A1

WO2018154931A1 - Centrifugal pump

Info

Publication number: WO2018154931A1
Application number: PCT/JP2017/044883
Authority: WO
Inventors: 淑孝松井
Original assignee: シナノケンシ株式会社
Priority date: 2017-02-22
Filing date: 2017-12-14
Publication date: 2018-08-30
Also published as: CN109154309A; EP3438463A4; US20190368495A1; JP2018135805A; EP3438463A1

Abstract

The present invention addresses the problem of providing a centrifugal pump with which thinning is achieved by using a radial gap type motor, with which flow passage losses from a suction flow passage to a discharge flow passage are small, and with which it is possible for heat generated in a coil to be dissipated efficiently without providing a special cooling structure. As a means of overcoming the problem, a rotor (13) and a pump main body (2) are disposed concentrically about a rotor shaft (7), and a suction side scroll flow passage (14) and a discharge side scroll flow passage (15) formed in the pump main body (2) communicate with one another by way of a central flow passage (10b), (10a) formed in the pump main body (2) and in an impeller (9).

Description

Centrifugal pump

The present invention relates to a centrifugal pump for circulating a cooling fluid, for example.

2. Description of the Related Art Conventionally, electronic devices such as notebook personal computers are provided with high heat-generating electronic components such as LEDs, CPUs, and MPUs, and centrifugal pumps are used for fluid circulation for cooling control circuits on which these are mounted.

Also, in order to promote the reduction in size and thickness of electronic equipment, it is necessary to reduce the thickness of the centrifugal pump. For this reason, the fluid suction side flow path for discharging the pressurized fluid from the circumferential direction by normally sucking the fluid from the axial center of the impeller and scrolling the fluid is bent by 90 ° so as to be parallel to the discharge side flow path. A formed centrifugal pump has been proposed (see Patent Document 1).

In addition, since a suction flow path is formed in the casing, the casing becomes thicker. Therefore, a centrifugal pump that uses an axial gap type motor instead of a radial gap type motor instead of a motor that rotates the impeller is also proposed. (See Patent Document 2).

JP 2001-132699 A JP 2009-8055 A

Although the centrifugal pump using the axial gap type motor described above can be thinned, the flow path on the suction side forms a flow path that is orthogonal to the inside of the base, and the cross-sectional area of the flow path is uniform. Therefore, the flow path loss is high. In particular, a back yoke equipped with a coil that constitutes an axial gap motor is molded and formed in the base, so the thickness of the base tends to increase, and the cross-sectional area of the suction side flow path formed in the base Is not widely available.
Further, since the suction side flow path flows into the pump chamber through the inside of the hollow fixed shaft of the impeller 4, it is necessary to form the suction side flow path across the back yoke in the radial direction. For this reason, since it is necessary to provide an intermittent part in the back yoke, a coil cannot be disposed in this part. Therefore, the amount of magnetic flux is reduced, the effective magnetic flux acting on the rotor is reduced, and the motor characteristics are likely to deteriorate.
Furthermore, since the suction side flow path is formed avoiding the coil, the heat generation of the coil cannot be efficiently released. If a cooling structure is provided separately, the thinning cannot be realized and the manufacturing cost increases.

The present invention has been made to solve these problems. The object of the present invention is to reduce the thickness of the flow path from the suction flow path to the discharge flow path by using a radial gap type motor. Another object of the present invention is to provide a centrifugal pump that can efficiently dissipate heat generated by a coil without providing a special cooling structure.

In order to achieve the above object, the present invention comprises the following arrangement.
A centrifugal pump that rotationally drives an impeller with a radial gap type electric motor to suck fluid into the pump chamber from the outer peripheral side of the pump body and discharge the fluid from the pump chamber from the outer peripheral side of the pump main body, the base portion, A rotor shaft that is supported by standing upright with at least one end prevented from being attached to the base portion, an impeller that is rotatably attached to the rotor shaft, and a rotor magnet that is concentrically assembled to the impeller. A rotor, a suction-side scroll passage that sucks fluid from the outer peripheral side of the impeller toward the radial center, and a discharge-side scroll passage that discharges fluid from the radial central portion of the impeller toward the outer periphery. A stator having a stator core formed with stator pole teeth disposed in a radial direction opposite to the rotor magnet is integrally assembled. A pump body, wherein the rotor and the pump body are arranged concentrically about the rotor shaft, and the suction-side scroll passage and the discharge-side scroll passage formed in the pump body Are communicated with each other through a central flow path formed in the pump body and the impeller.

According to the above centrifugal pump configuration, the suction-side scroll flow path and the discharge-side scroll flow path formed in the pump main body communicate with each other via the central flow path formed in the pump main body and the impeller. Thinning can also be realized using a type motor. In addition, there is little flow path loss from the suction-side scroll flow path to the discharge-side flow path scroll, and the fluid passes so as to surround both ends of the stator core in the axial direction. Can do.

The suction-side scroll flow path is partitioned so that a suction hole provided on the outer peripheral surface of the pump body and the fluid that has entered from the suction hole are guided toward the suction-side center hole while turning in the circumferential direction. It is preferable that a suction-side scroll groove is formed so that the groove depth becomes shallower from the suction hole toward the suction-side center hole.
As a result, the fluid sucked into the pump body from the suction hole is guided toward the suction-side center hole while turning along the suction-side scroll groove, and the groove depth gradually decreases toward the suction-side center hole. The fluid is guided axially to the impeller side through the central flow path. At this time, the height of the pump chamber is unnecessary, and even if the pump chamber is thinned, the flow path is not lost.

The suction-side scroll flow path is preferably formed between the suction-side scroll groove formed on one axial end surface of the pump body and the other base portion superimposed on the one axial end surface. .
As a result, the axial height of the pump main body can be suppressed, the reduction in thickness can be promoted, and the pump main body can be assembled on the base portion so that it can be assembled.

The discharge-side scroll channel includes a discharge-side center hole formed so as to communicate with the suction-side center hole via the center channel, and an outer periphery of the pump body while fluid swirls from the discharge-side center hole It is preferable to include a discharge-side scroll groove that is partitioned so as to be guided by a discharge hole provided on the surface and that has a groove depth that increases from the discharge-side center hole toward the discharge hole. .
As a result, the fluid sucked into the discharge side center hole from the central flow path is pressurized by the rotation of the impeller and guided to the discharge side scroll groove where the groove depth gradually increases from the discharge side center hole toward the discharge hole. The fluid is discharged from the discharge port. At this time, the height of the pump chamber is unnecessary, and even if the pump chamber is thinned, the flow path is not lost.

It is preferable that the discharge-side scroll flow path is formed between the discharge-side scroll groove formed on the other axial end surface of the pump body and one base portion superimposed on the other axial end surface.
As a result, the axial height of the pump body can be suppressed, the reduction in thickness can be promoted, and the pump body can be assembled on the base portion so that it can be assembled.

On the axial end face of the pump body, a shallow groove and a deep groove are combined so that the bottom of the groove is close to the suction side scroll flow path and the discharge side scroll flow path so that the fluid flow rate is uniform. It is preferable that
As a result, the suction-side scroll groove and the discharge-side scroll groove formed by partitioning in the radial direction in the pump chamber are combined so that the shallow groove and the deep groove are close to each other so that the flow velocity of the fluid is uniform. Therefore, the pump chamber volume does not increase in the axial direction, it is possible to promote thinning, and the flow path loss from the suction port to the discharge port is minimized. The pump performance can be maintained.

In the impeller, an annular portion to which the rotor is assembled and a blade portion to be assembled to the rotor shaft may be integrally formed.
Thereby, a rotor and an impeller can be assembled | attached simultaneously with respect to a rotor axis | shaft, and the arrangement | positioning of an axial direction can also be made compact.

A centrifugal pump that can be thinned using a radial gap type motor, has little flow loss from the suction flow path to the discharge flow path, and can efficiently dissipate the heat generated by the coil without providing a special cooling structure. Can be provided.

It is a perspective view of a centrifugal pump. FIG. 2 is a cross-sectional view in the direction of arrow XX in FIG. 1. FIG. 2 is a cross-sectional view in the direction of arrow YY in FIG. 1 and a top half view seen through the base portion. It is the suction side perspective view and discharge side perspective view of a pump main body.

Hereinafter, an embodiment of a centrifugal pump according to the present invention will be described with reference to the accompanying drawings shown in FIGS. In the present embodiment, a centrifugal pump that rotationally drives an impeller using a radial gap type inner rotor type motor will be described as an example. A DC brushless motor is used as the inner rotor type motor.

In FIG. 1, a centrifugal pump 1 is formed on the outer periphery of the pump body 2 by sucking fluid from a suction port 3 formed on the outer periphery of the pump body 2 by rotating the impeller 9 by a radial gap type electric motor M It discharges from the discharged outlet 4.
A pair of plate-

like base portions

5a and 5b are superposed so that both end faces of the resin-molded pump body 2 are sandwiched, and fixing bolts 6 are attached to the outer peripheral edge portions of the

base portions

5a and 5b facing each other via the pump body 2. Are assembled together by screw fitting.

Next, the structure of the centrifugal pump 1 will be described in detail with reference to FIG.
One end of the rotor shaft 7 is raised and supported and fixed to one base portion 5a of the pair of

base portions

5a and 5b. An impeller 9 is integrally assembled to the rotor shaft 7 via a sliding bearing 8. The impeller 9 is assembled integrally with the rotor shaft 7 by being secured to the other end of the rotor shaft 7 by a C-type retaining ring 7a via a thrust receiver 7b.

2 and 3B, the impeller 9 is integrally assembled with the rotor 13. The impeller 9 is integrally formed with an annular portion 9a that forms the central flow path 10a and a blade portion 9b that feeds fluid from the central portion toward the outer peripheral side. An annular back yoke 11 is attached to the outer peripheral surface of the annular portion 9a, and a rotor magnet 12 is integrally assembled to the outer peripheral side thereof by adhesion or insert molding. Thereby, the rotor 13 and the impeller 9 can be assembled | attached concentrically simultaneously with respect to the rotor shaft | axis 7, and the arrangement | positioning of an axial direction can also be made compact. The rotor magnet 12 may be a magnet formed in a ring shape in advance or a magnet divided into a plurality of segments. Further, a stepped portion 9c is formed in the suction side opening of the annular portion 9a. In the case where the impeller 9 and the rotor 13 are integrally formed, for example, it is preferable that the impeller 9 and the rotor 13 are integrally formed with PPS (polyphenylene sulfide) resin or the like in consideration of durability and the like.

Further, a central flow path 10a (hollow hole) is formed around the connecting portion of the impeller 9 with the rotor shaft 7 along the axial direction. As will be described later, the central flow path 10a is formed so as to communicate with the central flow path 10b formed in the pump body 2. That is, the suction-side scroll flow path 14 that sucks fluid from the outer peripheral side of the impeller 9 toward the radial center, and the discharge-side scroll flow path 15 that discharges fluid from the central part of the impeller 9 toward the outer peripheral side in the radial direction. Are communicated with each other through the

central flow paths

10a and 10b.

Next, the configuration of the pump body 2 will be described.
In FIG. 2, a suction-side scroll flow path 14 that sucks fluid in a radial direction from the outer peripheral side of the impeller 9 toward the center portion of the pump chamber 16 is formed at one axial end portion 2 a of the pump body 2. Specifically, the suction-side scroll channel 14 is overlapped with the suction-side scroll groove (concave portion) 14a formed in the axial one end 2a of the pump body 2 and the suction-side scroll groove 14a. And the base portion 5b to be assembled. Moreover, the axial direction one end part 2a is extended in the diameter direction inner side so that the annular part 9a of the impeller 9 may be extended, The lip | rip part 2c (turning structure) by which the edge part was formed in the L-shape is formed. The lip portion 2c is disposed so as to mesh with the stepped portion 9c of the annular portion 9a. The inner peripheral surface of the lip portion 2c forms a central flow path 10b that communicates with the central flow path 10a. Thereby, it is possible to prevent the fluid from flowing backward from the gap between the impeller 9 and the pump body 2 toward the central flow path 10a.

In FIG. 2, a discharge-side scroll passage 15 that discharges fluid in the radial direction from the center of the impeller 9 toward the outer peripheral side is formed at the other axial end 2 b of the pump body 2. Specifically, the discharge-side scroll passage 15 is formed between a discharge-side scroll groove (concave portion) 15a formed in the other axial end 2b of the pump body 2 and the base portion 5a. The pump chamber 16 provided in the pump body 2 is formed by connecting the suction-side scroll flow path 14 and the discharge-side scroll flow path 15 with the

central flow paths

10a and 10b. The suction-side scroll flow path 14 and the discharge-side scroll flow path 15 do not necessarily have to be formed between the axial end of the pump body 2 and the base portion, and are other members instead of the base portion. May be.

Further, as shown in FIG. 3A, a stator 17 is assembled to the pump body 2. The stator 17 includes a stator core 17c in which stator pole teeth 17b project radially from a radially inner side of the annular core back portion 17a. A coil 17d is wound around each stator pole tooth 17b.

As shown in FIGS. 3A and 3B, the pump body 2 is assembled to the

base portions

5a and 5b with the stator pole teeth 17b facing the rotor magnet 12 in the radial direction. The discharge-side scroll flow path 15 communicates with the

central flow paths

10b and 10a formed in the impeller 9.

According to the configuration of the centrifugal pump 1, the suction-side scroll flow path 14 that sucks fluid from the outer peripheral side of the impeller 9 (annular portion 9a) toward the radial center portion, and the central portion of the impeller 9 (blade portion 9b). Since the discharge-side scroll flow path 15 that discharges fluid in the radial direction toward the outer peripheral side communicates with the pump main body 2 and the

central flow paths

10b and 10a formed in the impeller 9, the radial gap type Thinning can be realized even using a motor. Further, since the passage loss from the suction-side scroll passage 14 to the discharge-side scroll passage 15 is small and the fluid passes so as to surround both end surfaces in the axial direction of the stator core 17c, the heat generation of the coil 17d is efficiently performed. It can dissipate heat well.

Next, the internal structure of the pump body 2 will be described with reference to FIG.
FIG. 4A is a perspective view showing the axial one end 2a of the pump body 2, in which a fluid suction side scroll channel 14 is formed. The fluid that has entered from the suction hole 14b provided on the outer peripheral surface of the pump body 2 is guided toward the suction-side center hole 14c while turning in the circumferential direction. The suction-side scroll groove 14a is partitioned by a partition wall 14d, and is formed by turning so that the groove depth gradually decreases from the suction hole 14b toward the suction-side center hole 14c (lip portion 2c: see FIG. 3B). ing.

Thereby, the fluid sucked into the pump chamber 16 through the suction hole 14b is guided toward the suction side center hole 14c while turning the suction side scroll groove 14a. At this time, since the groove depth gradually decreases toward the suction-side center hole 14c, the fluid is guided in the axial direction to the central flow path 10a on the impeller 9 side through the central flow path 10b. Even if the fluid moves in the pump body 2, the height of the pump chamber 16 is not required, and even if the pump body 2 is thinned, the flow path is not lost.

FIG. 5B is a perspective view showing the other axial end 2b of the pump body 2, in which a fluid discharge side scroll channel 15 is formed. The fluid flowing in from the discharge-side center hole 15b through the central flow path 10a is guided to the discharge hole 15c provided on the outer peripheral surface of the pump body 2 while turning in the circumferential direction along the blade portion 9b of the impeller 9. The discharge-side scroll groove 15a is partitioned by a partition wall 15d, and is formed by turning so that the groove depth gradually increases from the discharge-side center hole 15b toward the discharge hole 15c.

Thereby, the fluid flowing into the discharge side center hole 15b from the central flow path 10a is pressurized by the rotation of the impeller 9 (blade portion 9b) and guided toward the outer peripheral surface of the pump body 2. That is, the pressurized fluid is sent while being swung along the discharge side scroll groove 15a in which the groove depth gradually increases from the discharge side central hole 15b toward the discharge hole 15c, and is discharged from the discharge port 4. At this time, even if the fluid of the pump body 2 is swung, the height of the pump chamber 16 is not required and even if the pump body 2 is thinned, the flow path is not lost.

The axial end surface of the pump body 2 is preferably formed so that the grooves are arranged in a point-symmetric manner so that the flow velocity of the fluid flowing through the suction-side scroll groove 14a and the discharge-side scroll groove 15a is uniform. . Specifically, as shown in FIGS. 2 and 3B, the suction-side scroll groove 14a and the discharge-side scroll groove 15a are combined so that the shallow groove and the deep groove are close to the groove bottom on the axial end surface of the pump body 2. Is formed.

As described above, the axial end surface of the pump body 2 is shallow so that the flow velocity of the fluid flowing through the suction-side scroll groove 14a and the discharge-side scroll groove 15a formed by being partitioned in the radial direction in the pump chamber 16 is uniform. Since the groove and the deep groove are formed in combination, the volume of the pump chamber 16 does not increase in the axial direction, and the reduction in thickness can be promoted. In addition, from the suction port 3 to the discharge port 4 The flow path loss can be reduced as much as possible, and the pump performance can be maintained.

In FIG. 1, it is preferable that annular seal materials 18 and 19 (O-rings or the like) are provided between the pair of

base portions

5a and 5b that are superposed on the pump body 2. Thereby, the sealing performance of the fluid of the suction side scroll flow path 14 and the discharge side scroll flow path 15 can be improved.

Here, an example of the fluid delivery operation of the centrifugal pump 1 will be described.
In FIG. 2, when the electric motor is started, the impeller 9 assembled integrally with the rotor shaft 8 is rotationally driven.
As a result, fluid is sucked from the suction port 3 through the suction-side scroll passage 14, and the fluid sucked into the pump chamber 16 from the suction hole 14b is guided to the suction-side scroll groove 14a and turns into the suction-side central hole 14c. (See FIG. 4A).

Then, the fluid is sent out from the suction side center hole 14c to the discharge side center hole 15b through the

central flow paths

10b and 10a (see FIG. 3B). The fluid flowing into the discharge side center hole 15b from the central flow path 10a is guided toward the outer peripheral surface of the pump body 2 while turning the discharge side scroll groove 15a by the rotation of the impeller 9, and is discharged from the discharge side center hole 15b to the discharge side. Pressure is applied to the discharge hole 15c through the scroll flow path 15, and the liquid is discharged from the discharge port 4 (see FIG. 4B).

As described above, a radial gap type electric motor is used to reduce the thickness of the coil 17d so that the passage loss from the suction-side scroll passage 14 to the discharge-side scroll passage 15 is small, and the heat generation of the coil 17d is exceptional. Thus, it is possible to provide the centrifugal pump 1 that can efficiently dissipate heat.

In the above-described embodiment, the impeller 9 assembled concentrically with the rotor shaft 8 as the center has the annular portion 9a and the blade portion 9b integrally formed of resin, but may be constituted by separate parts.
Further, although the rotor shaft 8 is fixed and the rotor 13 and the impeller 9 are rotated, the rotor 13 and the impeller 9 may be rotated together with the rotor shaft 8.

Claims

A centrifugal pump that rotates and drives an impeller by a radial gap type electric motor, sucks fluid into the pump chamber from the outer peripheral side of the pump body, and discharges the fluid from the outer peripheral side of the pump body from the pump chamber,
A base part;
A rotor shaft that is supported upright with at least one end being prevented from being detached from the base portion, and an impeller that is rotatably attached to the rotor shaft;
A rotor comprising a rotor magnet concentrically assembled to the impeller;
A suction-side scroll flow path for sucking fluid from the outer peripheral side of the impeller toward the radial center; a discharge-side scroll flow path for discharging fluid from the radial central part of the impeller toward the outer periphery; and the rotor The pump body integrally assembled with a stator having a stator core formed with stator pole teeth that are arranged to be opposed to the magnet in the radial direction; and
The rotor and the pump body are arranged concentrically about the rotor shaft, and the suction-side scroll passage and the discharge-side scroll passage formed in the pump body include the pump body and the impeller. A centrifugal pump characterized in that it is communicated through a central flow path formed in the above.
The suction-side scroll flow path is partitioned so that a suction hole provided on the outer peripheral surface of the pump body and the fluid that has entered from the suction hole are guided toward the suction-side center hole while turning in the circumferential direction. The centrifugal pump according to claim 1, further comprising a suction-side scroll groove formed so that a groove depth becomes shallower from the suction hole toward the suction-side center hole.
The centrifuge according to claim 2, wherein the suction-side scroll flow path is formed between the suction-side scroll groove formed at one axial end portion of the pump body and a base portion overlapped with the one axial end portion. pump.
The discharge-side scroll flow path is formed on the outer peripheral surface of the pump body while turning from the discharge-side center hole and the discharge-side center hole formed so as to communicate with the suction-side center hole via the central flow path. The discharge-side scroll groove that is partitioned so as to be guided by the provided discharge hole and that has a groove depth that increases from the discharge-side center hole toward the discharge hole. Item 4. The centrifugal pump according to any one of Items 3.
5. The discharge-side scroll flow path is formed between the discharge-side scroll groove formed at the other axial end portion of the pump body and a base portion overlapped with the other axial end portion. The centrifugal pump according to item.
On the axial end face of the pump body, a shallow groove and a deep groove are combined so that the bottom of the groove is close to the suction side scroll flow path and the discharge side scroll flow path so that the fluid flow rate is uniform. The centrifugal pump according to any one of claims 1 to 5, wherein:
The centrifugal pump according to any one of claims 1 to 6, wherein the impeller is integrally formed with an annular portion to which the rotor is assembled and a blade portion to be assembled with the rotor shaft.